Active material elements may provide the mechanical impetus to operate mechanisms of various kinds. One suitable family of such active material elements is Shape Memory Alloys. Linear mechanical actuators incorporating active elements of shape memory alloy (SMA) compositions have been used in a variety of devices, many of which have been conceived for use on automotive vehicles. For example, U.S. Pat. Nos. 7,607,717, 7,686,382, and 8,188,757, and Patent Application Publications 2012/0174573 and 2012/0184195, each assigned to the assignee of this invention, describe and illustrate a number of on-vehicle devices using linear mechanical actuators formed of shape memory alloys such as nickel-titanium based alloys. The portions of these patent disclosures pertaining to compositions, shapes, and functions of shape memory alloy, mechanical actuators for devices are incorporated herein by reference. These documents describe and illustrate that movable air flow dams, air flow spoilers, and baffle controllers within Heating Ventilation Air Conditioning (HVAC) outlet housings are examples of on-vehicle devices that may be set in motion by linear SMA actuators.
These SMA elements undergo a transformation of their crystal structure over a narrow and selectable temperature range. In transforming from the lower temperature phase to the higher temperature phase the SMA element, or other similar elongated form, seeks to contract. If such contraction is opposed, the SMA element will seek to overcome the opposition and in so doing generate appreciable force. This force which, when harnessed and transmitted, may power and operate the above-listed mechanisms and devices, among others.
It will be appreciated that the force generated must be coupled to the mechanism. Generally this is accomplished by first coupling the SMA element to a connector shaped and adapted to couple to the mechanism, and then suitably attaching the connector, with its attached linear SMA element, to the mechanism. Thus a robust and reliable joint must be made between the SMA element and its associated connector.